Device and method for high-pressure water jetting surface cutting

ABSTRACT

This invention provides a cutting device which includes a high pressure water jet nozzle head capable of being moved in X and Y directions while being rotated, and which cuts a resin matrix portion on a surface of a composite molded article consisting of inorganic particles and a resin by a high pressure water jet, wherein a plurality of high pressure water jet nozzles are arranged in the nozzle head, and high pressure water jet centers of at least one or more nozzles are arranged at inclined angles with respect to perpendicular positions to a foundation layer surface of the composite molded article. Even a resin matrix surface layer in an inclined portion of an irregular surface shape or a relief pattern can be effectively cut away.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a high pressure water jet surfacecutting device and a surface cutting method. More specifically, thepresent invention relates to a novel surface cutting device by means ofa high pressure water jet useful for an irregular surface shape of acomposite molded article to be used as a building material, e.g., aninterior or an exterior wall material, a pavement, an artificial stonefor a monument or the like, or useful for surface finishing of a reliefpattern, and a surface cutting method using this novel surface cuttingdevice.

2. Description of the Related Art

Conventionally, there are known composite molded articles made of amixture of a resin component, a natural stone or its ground powders, andinorganic particles such as particles of a synthetic inorganic compoundand similar to marble, an artificial stone similar to a natural stone,and the like. Various blending ratios of materials, various color tones,and various uses of these composite molded articles have been alsoproposed.

Normally, each of the composite molded articles is provided as a productby injecting the resin mixture into a molding die, hardening the resinmixture, and detaching the hardened resin mixture from the molding die.During the molding, an irregular shape or a relief pattern is added to asurface of the composite molded article so as to realize a texture of anatural stone or a three-dimension of the surface, or a shading depth.

During the conventional molding of the composite article consisting ofthe artificial stone or the like, for example, a thin film resin matrixsurface layer 2 as shown in FIG. 1 is present on the surface of thecomposite molded article 1. Therefore, this resin matrix surface layer 2is removed by the high pressure water jet, a dissolving treatment usingchemicals or the like. This resin matrix surface layer 2 is formed,following cast molding using this molding die. If this resin matrixsurface layer 2 is left, the surface of the composite molding article 1inevitably gives a resin (plastic) texture. To prevent this, this resinmatrix surface layer 2 is removed to thereby expose the natural stonepowders and mineral particles contained in the composite molded article1 consisting of the artificial stone or the like.

The dissolving treatment using chemicals casts a major burden onenvironment in terms of waste liquid or the like and is not, therefore,undesirable. In order to remove the resin matrix surface layer 2, it isconsidered to be practical to cut away the resin matrix surface layer 2by the high pressure water jet that exhibits a good resin matrix surfacelayer removal effect.

Although this high pressure water jet is basically effective as cuttingmeans for the resin matrix surface layer 2, it leaves much room forimprovement for a surface, finishing treatment to the composite moldedarticle 1 at higher quality with a sense of high end. For the compositemolded article 1 that has the irregular surface shape or the reliefsurface pattern as shown in FIG. 1, for example, the surface cutting ina vertex portion 11 and a flat portion 12 can be satisfactorilyperformed; however, the surface cutting in an inclined portion 13 isconventionally, unavoidably insufficient. Due to this, the resin matrixsurface layer 2 is left in the inclined portion 13. As a result, it isdisadvantageously difficult to provide a high-quality composite moldedarticle that imparts a three-dimensional shading, a texture of a naturalstone, an excellent design form, and a good aesthetic sense.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide noveltechnical measures capable of solving the disadvantages of conventionalsurface cutting devices by means of a high pressure water jet, andeffectively cutting away a resin matrix surface layer in an inclinedportion of an irregular surface shape or a relief pattern.

According to the first aspect of the present invention, there isprovided a high pressure water jet surface cutting device that comprisesa high pressure water jet nozzle head which can be moved in X and Ydirections while being rotated, and that cuts a resin matrix portion ona surface of a composite molded article consisting of inorganicparticles and a resin, characterized in that a plurality of highpressure water jet nozzles are arranged on the nozzle head, highpressure water jet centers of at least one or more nozzles beingarranged at inclined angles with respect to perpendicular positions to afoundation layer surface of the composite molded article, respectively.

According to the second aspect of the present invention, there isprovided the high pressure water jet surface cutting devicecharacterized in that the inclined angles of the at least one or morenozzles are within a range of 45°. According to the third aspect of thepresent invention, there is provided the high pressure water jet surfacecutting device characterized in that the at least one or more nozzlesarranged at the inclined angles are at orthogonal positions to a tangentof the nozzle head to be directed outward of a rotation center of thenozzle head or directed inward toward the rotation center. According toa fourth aspect of the present invention, there is provided the highpressure water jet surface cutting device characterized in that the atleast one or more nozzles are arranged so that the jet centers are atperpendicular positions at the inclined angles of 0° with respect to thefoundation layer surface.

According to the fifth aspect of the present invention, there isprovided the high pressure water jet surface cutting devicecharacterized in that the plurality of high pressure water jet nozzlesare arranged at at least two or more circumferential positions havingdifferent distances from the rotation center of the nozzle head.According to the sixth aspect of the present invention, there isprovided the high pressure water jet surface cutting devicecharacterized in that the plurality of nozzles arranged at an equalcircumferential position are arranged at symmetric positions about therotation center of the nozzle head. According to the seventh aspect ofthe present invention, there is provided the high pressure water jetsurface cutting device characterized in that the plurality of nozzlesarranged at the equal circumferential position are arranged at the sameinclined angle or equally perpendicularly, and form an equal arrangementangle with respect to a tangent. According to the eighth aspect of thepresent invention, there is provided the high pressure water jet surfacecutting device characterized in that the nozzles arranged at a pluralityof circumferential positions, respectively, differ in inclined angle.

According to a ninth aspect of the present invention, there is provideda surface cutting method using the surface cutting device according toany one of the first to the eighth aspects of the present invention,characterized by comprising a step of cutting the resin matrix portionon the surface of the composite molded article while moving the nozzlehead in the X and Y directions so that areas among loci of the jetcenters with respect to the foundation layer surface of the compositemolded article against which a jet water from the nozzles is strickenare uniform. According to the tenth aspect of the present invention,there is provided the high pressure water jet surface cutting devicecharacterized by comprising a step of cutting away the resin matrixportion having a thickness within a range of 10 μm to 10 mm. Accordingto the eleventh aspect of the present invention, there is provided thehigh pressure water jet surface cutting device characterized bycomprising a step of cutting the surface of the composite molded articlethat includes irregular surfaces having a height from the foundationlayer surface within a range of 1 to 100 mm.

The invention according to the present invention constituted as statedabove is completed based on the following new knowledge obtained as aresult of detailed and specific studies conducted by the inventors ofthe present invention.

According to the studies of the inventors of the present invention, whenthe resin matrix surface layer 2 is cut by the conventional highpressure water jet, the number of jet nozzles provided on the rotarydisk is increased and the number of revolutions (circumferential speed)of each nozzle is increased. By so increasing, the impact energy of thehigh pressure water, with which the high pressure water is strickenagainst the surface of the composite molded article 1, is uniformlydistributed to the vertex portion 11, the flat portion 12, and theinclined portion 13. However, there is a limit to the removal of theresin matrix surface layer 2 in the inclined portion 13 by cutting. Thesame thing is true when the pressure of the jet water is increased. Ifthe pressure is excessively increased, the vertex portion 11 and theflat portion 12 may possibly be damaged. By contrast, if the centers ofthe high pressure water jet nozzles are arranged at the inclined angleswith respect to perpendicular positions to the foundation layer surfaceof the composite molded article 1, which is composed by the foundationlayer portion 1A and an additional decoration portion 1B, as shown inFIG. 1, that is, at perpendicular positions to the flat portion 12,shown in FIG. 1, in place of the conventional jet nozzles that arearranged perpendicularly, that is, arranged so that the high pressurewater can be stricken against the inclined portion 13 substantiallyperpendicularly, the resin matrix surface layer 2 in the inclinedportion 13 can be satisfactorily cut away. It is also discovered fromthe studies that, if nozzles for injecting the high pressure water in aperpendicular direction to the foundation layer surface, i.e., the flatportion 12 are additionally provided, the resin matrix surface layer 2in the vertex portion 11 and the flat portion 12 can be also,satisfactorily cut away. This cannot be predicted at all from theconventional knowledge and experience.

Thus, the present invention is completed based on this knowledge, andcompleted further by deepening this knowledge and considering mostpreferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view and a partially enlarged view whichshow one example of a composite molded article;

FIG. 2 is a bottom view which shows a nozzle head;

FIG. 3 is a cross-sectional view taken along A-A of FIG. 2; and

FIG. 4 shows loci formed following rotational movement of the nozzlehead.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will be described hereinafterwith reference to the drawings.

A high pressure water jet surface cutting device according to thepresent invention is characterized in that high pressure jet centers ofat least one or more nozzles are located at inclined angles with respectto perpendicular positions. This feature can be embodied by, forexample, FIGS. 2 and 3.

FIG. 2 is a bottom view which shows an example of a state in which aplurality of high pressure water jet nozzles 3 are arranged on a rotarydisk 4. FIG. 3 is a cross-sectional view taken along A-A of FIG. 2.

According to this embodiment, for example, in the high pressure waterjet surface cutting device, a plurality of high pressure water jetnozzles 3 are arranged on the rotary disk 4 of the nozzle head. At leastone or more nozzles 3., eg., high pressure water jet centers of at leastone or more nozzles 3AC and 3BC of high pressure water jet nozzles 3Aand 3B shown in FIG. 3 are arranged at inclined angles θ_(A) and θ_(B)with respect to perpendicular positions to a foundation layer surface ofthe composite molded article, respectively.

More specifically, the high pressure water jet nozzle 3A is arranged atthe inclined angle θ_(A) while being radiated outward of the rotationcenter of the rotary disk 4. The high pressure water jet nozzle 3B isarranged at the inclined angle θ_(B) while being directed toward therotation center thereof. The cutting device according to the presentinvention has preferably the inclined angles θ_(A) and θ_(B) within arange of 45°.

In the cutting device, each nozzle arranged at such an inclined anglemay form an arbitrary angle within a range of 360°, e.g., an angle of0°, with respect to, for example, a tangent H of the rotary disk 4 ofthe nozzle head as shown in FIG. 2 in plane arrangement. FIGS. 2 and 3depict, as a preferred embodiment, a specific example in which thenozzle 3A that forms an angle of +90° with respect to the tangent H,i.e., that is arranged at an orthogonal position to the tangent H whilebeing radiated outward of the rotation center of the rotary disk 4, andin which the nozzle 3B that forms an angle of −90° with respect to thetangent H, i.e., that is arranged at an orthogonal position to thetangent H while being directed toward the rotation center thereof.

Actually, according to the present invention, the plural high pressurewater jet nozzles 3 are preferably arranged at two or morecircumferential positions at different distances from the rotationcenter of the rotary disk 4 of the nozzle head, the circumferentialpositions different in inclined angle. The nozzles 3 at the samecircumferential position are preferably arranged symmetrically about therotation center of the rotary disk 4, and at the same plane positionwith respect to the tangent H at the same inclined angle.

For instance, the surface cutting device that includes the nozzle headcorresponding to the example of FIGS. 2 and 3 and being constituted ofsuch conditions that the rotary disk 4 has an outside diameter of 220mm, a distance from the rotation center on an inner circumference shownin FIG. 2 is 175 mm, a distance from the rotation center on an outercircumference shown in FIG. 2 is 200 mm, a nozzle injection caliber is0.2 mm, and that the inclined angles θ_(A) and θ_(B) are 20° isprovided. Further, the surface cutting device in which circumferentialpositions of the two nozzles arranged at symmetric positions from therotation center are divided to six stages of 160, 165, 175, 185, 190,and 200 mm, is specifically provided.

According to the present invention, when the surface of the compositemolded article consisting of the inorganic particles and the resin iscut using the cutting device that includes such a nozzle head, thenozzle head is rotated to be moved in X and Y directions. In this case,as shown in, for example, FIG. 4, maximum widths A_(max), B_(max),C_(max), and D_(max) of loci of nozzles A, B, C, and D following therotation movement of the nozzles A, B, C, and D in the Y direction aredetermined according to arrangement positions of the respective nozzles.Preferably, therefore, the nozzles are arranged at positions differentin distance from the rotation center of the nozzle head as much aspossible, thereby making areas among the loci small and uniform.Further, by setting a movement pitch in the X direction to be small, theareas among the loci can be made smaller and more uniform.

The movement of the nozzle head may be either a continuous movement or astep-by-step movement.

For example, the instance of using the nozzle head in which thecircumferential positions are divided to the six positions set forthabove will be described. For this nozzle head, the following conditionsare set.

A height of the nozzle from the surface of the composite molded article:35 mm

A jet water pressure: 1,500 kgf/cm²

A Y-direction feeding velocity: 15,000 mm/min

An X-direction feeding velocity: 60 mm/min

The number of revolutions of the nozzle head: 750 rpm.

By satisfying these conditions, a PMAA resin matrix surface layer (at athickness of 200 μm) can be satisfactorily cut in all of the vertexportion, the flat portion, and the inclined portion of the irregularsurface shape. If the conventional nozzle head having as many nozzles asthose according to the present invention is employed, and it is set thata predetermined matrix surface layer can be cut in the flat portion,then the matrix surface layer in the inclined portion is hardly cut butleft within the same time. If a setting is made that the water jetpressure is higher and the distance between each nozzle and the moldedarticle is shorter so that the inclined portion is cut by apredetermined cutting thickness, then the flat portion is excessivelycut.

Needless to say, the present invention is not limited to the embodiment,and various forms of the detailed parts of the invention can be adopted.

As described so far in detail, the present invention can solve thedisadvantages of the conventional surface cutting means by the highpressure water jet, and effectively cut away the resin matrix surfacelayer in the inclined portion of the irregular surface shape or therelief design.

1. A high pressure water jet surface cutting device that comprises ahigh pressure water jet nozzle head which can be moved in X and Ydirections while being rotated, and that cuts a resin matrix portion ona surface of a composite molded article consisting of inorganicparticles and a resin, wherein a plurality of high pressure water jetnozzles are arranged on said nozzle head, high pressure water jetcenters of at least one or more nozzles being arranged at inclinedangles with respect to perpendicular positions to a foundation layersurface of said composite molded article, respectively.
 2. The highpressure water jet surface cutting device according to claim 1, whereinthe inclined angles of the at least one or more nozzles are within arange of 45°.
 3. The high pressure water jet surface cutting deviceaccording to claim 1, wherein the at least one or more nozzles arrangedat the inclined angles are at orthogonal positions to a tangent of thenozzle head to be directed outward of a rotation center of the nozzlehead or directed inward toward the rotation center.
 4. The high pressurewater jet surface cutting device according to claim 1, wherein the atleast one or more nozzles are arranged so that the jet centers are atperpendicular positions at the inclined angles of 0° with respect to thefoundation layer surface.
 5. The high pressure water jet surface cuttingdevice according to claim 1, wherein the plurality of high pressurewater jet nozzles are arranged at at least two or more circumferentialpositions having different distances from the rotation center of thenozzle head.
 6. The high pressure water jet surface cutting deviceaccording to claim 5, wherein the plurality of nozzles arranged at anequal circumferential position are arranged at symmetric positions aboutthe rotation center of the nozzle head.
 7. The high pressure water jetsurface cutting device according to claim 5, wherein the plurality ofnozzles arranged at the equal circumferential position are arranged atthe same inclined angle or equally perpendicularly, and form an equalarrangement angle with respect to a tangent.
 8. The high pressure waterjet surface cutting device according to claim 5, wherein the nozzlesarranged at a plurality of circumferential positions, respectively,differ in inclined angle.
 9. A surface cutting method using the surfacecutting device according to claim 1, comprising a step of: cutting theresin matrix portion on the surface of the composite molded articlewhile moving the nozzle head in the X and Y directions so that areasamong loci of the jet centers with respect to the foundation layersurface of said composite molded article against which a jet water fromthe nozzles is stricken are uniform.
 10. The cutting method according toclaim 9, comprising a step of cutting away the resin matrix portionhaving a thickness within a range of 10 μm to 10 mm.
 11. The cuttingmethod according to claim 9, comprising a step of cutting the surface ofthe composite molded article that includes an irregular surface having aheight from the foundation layer surface within a range of 1 to 100 mm.12. The high pressure water jet surface cutting device according toclaim 2, wherein the at least one or more nozzles arranged at theinclined angles are at orthogonal positions to a tangent of the nozzlehead to be directed outward of a rotation center of the nozzle head ordirected inward toward the rotation center.
 13. The high pressure waterjet surface cutting device according to claim 2, wherein the at leastone or more nozzles are arranged so that the jet centers are atperpendicular positions at the inclined angles of 0° with respect to thefoundation layer surface.
 14. The high pressure water jet surfacecutting device according to claim 3, wherein the at least one or morenozzles are arranged so that the jet centers are at perpendicularpositions at the inclined angles of 0° with respect to the foundationlayer surface.
 15. The high pressure water jet surface cutting deviceaccording to claim 2, wherein the plurality of high pressure water jetnozzles are arranged at at least two or more circumferential positionshaving different distances from the rotation center of the nozzle head.16. The high pressure water jet surface cutting device according toclaim 3, wherein the plurality of high pressure water jet nozzles arearranged at at least two or more circumferential positions havingdifferent distances from the rotation center of the nozzle head.
 17. Thehigh pressure water jet surface cutting device according to claim 4,wherein the plurality of high pressure water jet nozzles are arranged atat least two or more circumferential positions having differentdistances from the rotation center of the nozzle head.
 18. The highpressure water jet surface cutting device according to claim 6, whereinthe plurality of nozzles arranged at the equal circumferential positionare arranged at the same inclined angle or equally perpendicularly, andform an equal arrangement angle with respect to a tangent.
 19. The highpressure water jet surface cutting device according to claim 6, whereinthe nozzles arranged at a plurality of circumferential positions,respectively, differ in inclined angle.
 20. The high pressure water jetsurface cutting device according to claim 7, wherein the nozzlesarranged at a plurality of circumferential positions, respectively,differ in inclined angle.